Our young detective couple, JC and Susan Shelby, embarks in Chicago on a small ship tour of the Great Lakes, the Erie Canal, Hudson River, and Manhattan. What should have been a much deserved rest from their arduous immediately past adventures turns into a nightmare experience with death at Niagara Falls among other places along their colorful tour route. A large group of fellow passengers, a family of seven from North Dakota celebrating an inheritance with a hopefully pleasant vacation, begin to have some very bad luck death strikes in a mysterious fashion. JCs rank as a Navy Lieutenant in Intel service of the US Navy and the Shelbys past success in solving murder crimes results in their being put on the case by the FBI where they struggle with a series of disappearing suspects. The case finally ends, not in Rhode Island at the end of the cruise where everyone was sure it would, but in Arizona and New York City.